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From: Jelte Fennema-Nio <postgres@jeltef.nl>
Date: Fri, 1 Mar 2024 05:43:25 +0100
Message-ID: <CAGECzQScYZLUrmxj2hHpkqZTSxmP+m4M5YgbT9Log6cytVfq4w@mail.gmail.com>
Subject: Re: ALTER TABLE SET ACCESS METHOD on partitioned tables
To: Michael Paquier <michael@paquier.xyz>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Peter Eisentraut <peter@eisentraut.org>, 
	Soumyadeep Chakraborty <soumyadeep2007@gmail.com>, Zhihong Yu <zyu@yugabyte.com>, 
	pgsql-hackers@postgresql.org, Ashwin Agrawal <ashwinstar@gmail.com>, vanjared@vmware.com
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On Fri, 1 Mar 2024 at 02:57, Michael Paquier <michael@paquier.xyz> wrote:
> When it comes to partitioned tables, there is a still a tricky case:
> what should we do when a user specifies a non-default value in the SET
> ACCESS METHOD clause and it matches default_table_access_method?
> Should the relam be 0 or should we force relam to be the OID of the
> given value given by the query?  Implementation-wise, forcing the
> value to 0 is simpler, but I can get why it could be confusing as
> well, because the state of the catalogs does not reflect what was
> provided in the query.  At the same time, the user has explicitly set
> the access method to be the same as the default, so perhaps 0 makes
> sense anyway in this case.

I think we should set the AM OID explicitly. Because an important
thing to consider is: What behaviour makes sense when later
default_table_access_method is changed?
I think if someone sets it explicitly on the partitioned table, they
would want the AM of the partitioned table to stay the same when
default_table_access_method is changed. Which requires storing the AM
OID afaict.